AME5250A 1A, 1.5MHz Synchronous Step-Down

AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n General Description
The AME5250A is a high efficiency monolithic synchronous buck regulator using a constant frequency, current
mode architecture. Capable of delivering 1A output current over a wide input voltage range from 2.5V to 5.5V.
Supply current with no load is 400µA and drops to<1µA
in shutdown.The 2.5V to 5.5V input Voltage range makes
the AME5250A ideally suited for single Li-Ion batterypowered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
PWM pulse skipping mode operation provides very low
output ripple voltage for noise sensitive applications. At
very light load, the AME5250A will automatically skip
pulses in pulse skip mode operation to maintain output
regulation.
The internal synchronous switch increases efficiency
and eliminates the need for an external Schottky diode.
Low output voltages are easily supported with the 0.6V
feedback reference voltage. The AME5250A is available
in small DFN-6D & QFN-16C packages.
Other features include soft start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection.
n Applications
l
l
l
l
l
Cellular Telephones
Personal Information Appliances
Wireless and DSL Modems
MP3 Players
Portable Instruments
n Typical Application
2.2µH
VIN
IN
AME5250 A
CIN
4.7µF
CER
EN
Rev.A.03
OUT
Figure 1. High Efficiency Step-Down Converter
VIN
2.5V to 5.5V
n Features
High Efficiency: Up to 95%
Shutdown Mode Draws <1µA Supply Current
2.5V to 5.5V Input Range
Adjustable Output From 0.6V to VIN
1.0V, 1.2V, 1.5V, 1.6V, 1.8V, 2.5V and
3.3V Fixed/Adjustable Output Voltage
l 1A Output Current
l Low Dropout Operation: 100% Duty Cycle
l No Schottky Diode Required
l 1.5MHz Constant Frequency PWM Operation
l Small DFN-6D & QFN-16C Packages
l All AME’ s Lead Free Product Meet RoHS
Standard
GND
COUT
10µF
CER
Fixed Output Voltage
2.2µH
IN
l
l
l
l
l
VOUT
SW
SW
AME5250 A
CIN
4.7µF
CER
EN
CFWD
FB
GND
VOUT
1.8V
R1
1000mA
150K
COUT
10µF
CER
R2
75K
VOUT =VFB (R1+R2)/R2
Adjustable Output Voltage
Figure 2. 1.8V at 1000mA Step-Down Requlator
CFWD: 22pF~220pF
1
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Function Block Diagram
Constant
Off -time
Mode
Select
Slope
COMP
VIN
IN
3
PWM
COMP
FB/ OUT
6
0.6V
0. 6V
VREF
SW
LOGIC
4
0. 55V
UVDET
Soft
Start
EN
2
OSC
NMOS
COMP
IRCOM
P
GND
5
Figure 3. Founction Block Diagram
2
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Pin Configuration
10
9
AME5250A
16
3
15
2
14
1
11
13
AME5250A
12
8
4
7
5
6
6
AME5250A-AVYxxx
1. NC
2. EN
3. IN
4. SW
5. GND
6. FB/OUT
QFN-16C
(3mmx3mmx0.75mm)
Top View
5
DFN-6D
(2mmx2mmx0.75mm)
Top View
1
2
3
4
AME5250A-AWExxx
9. IN
1. GND
10. IN
2. GND
11. IN
3. GND
12. IN
4. FB/OUT
13. SW
5. GND
14. SW
6. NC
15. SW
7. EN
16. NC
8. NC
* Die Attach:
Conductive Epoxy
* Die Attach:
Conductive Epoxy
Note:
The area enclosed by dashed line represents Exposed Pad and connect to GND.
n Pin Description
Pin Number
Rev.A.03
Pin Name
Pin Description
DFN
QFN
1
6, 8, 16
NC
No connection. Not internally connected. Can left floating or
connected to GND.
2
7
EN
Enable Control Input, active high.
3
9, 10, 11, 12
IN
Input Supply Voltage Pin.
Bypass this pin with a capacitor as close to the device as
possible.
4
13, 14, 15
SW
Switch Node Connection to Inductor.
5
1, 2, 3, 5
GND
Ground. Tie directly to ground plane.
6
4
FB/OUT
Output voltage Feedback input.
3
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Ordering Information
AME5250A - x x x xxx
Output Voltage
Number of Pins
Package Type
Pin Configuration & Special Feature
Pin Configuration &
Special Feature
A
(DFN-6D)
A
(QFN-16C)
4
1.
2.
3.
4.
5.
6.
NC
EN
IN
SW
GND
FB/OUT
1. GND
2. GND
3. GND
4. FB/OUT
5. GND
6. NC
7. EN
8. NC
9. IN
10. IN
11. IN
12. IN
13. SW
14. SW
15. SW
16. NC
Package
Type
V: DFN
W: QFN
Number of
Pins
Y: 6
E: 16
Output Voltage
100:
120:
150:
160:
180:
250:
330:
ADJ:
1.0V
1.2V
1.5V
1.6V
1.8V
2.5V
3.3V
Adjustable
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Absolute Maximum Ratings
Parameter
Symbol
Maximum
V IN
-0.3 to 6.5
V EN , VOUT
-0.3 to VIN
VSW
-0.3 to VIN
Input Supply Voltage
EN, VOUT Voltage
SW Voltage
Unit
V
B*
ESD Classification
Caution: Stress above the listed absolute maximum rating may cause permanent damage to the device.
* HBM B: 2000V~3999V
n Recommended Operating Conditions
Parameter
Symbol
Rating
Unit
Supply Voltage Voltage
VIN
2.5 to 5.5
V
Ambient Temperature Range
TA
-40 to +85
o
C
Junction Temperature Range
TJ
-40 to +125
o
C
Rev.A.03
5
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Thermal Information
Parameter
Package
Die Attach
Thermal Resistance*
(Junction to Case)
Thermal Resistance
(Junction to Ambient)
Symbol
Maximum
θJ C
85
o
DFN-6D
Conductive Epoxy
θJA
160
Internal Power Dissipation
PD
625
Thermal Resistance*
(Junction to Case)
θJ C
67
Thermal Resistance
(Junction to Ambient)
Unit
mW
o
QFN-16C
Internal Power Dissipation
Solder Iron (10Sec)**
Conductive Epoxy
θJA
149
PD
670
350
C/W
C/W
mW
o
C
* Measure θJC on backside center of Exposed Pad.
** MIL-STD-202G 210F
6
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Electrical Specifications
VIN=3.6V, VOUT=2.5V, VFB=0.6V, L=2.2µH, CIN=4.7µF, COUT=10µF, TA=25oC, IMAX=1A unless otherwise specified.
Parameter
Input voltage
Symbol
Test Condition
VIN
VIN=2.5 to 5.5V, in PWM mode
For Fixed Output Voltage
Min
Typ
Max
Units
2.5
5.5
V
-3
3
%
VFB
VIN-0.2
V
0.612
V
50
nA
Output Voltage Accuracy
∆VOUT
Adjustable Output Range
Vout
Feedback Voltage
VFB
For Adjustable OutputVoltage
0.588
Feedback Pin Bias Current
IFB
VFB=VIN
-50
Quiescent Current
IQ
IOUT=0mA, VFB=1V
0.4
0.5
mA
Shutdown Current
ISHDN
VEN=GND
0.1
1
µA
Switch Frequency
fOSC
1.5
1.8
MHz
1.2
0.6
High-side Switch On-Resistance
RDS,ON, LHI
ISW=200mA, VIN=3.6V
0.28
Ω
Low-side Switch On-Resistance
RDS,ON, LO
ISW=200mA, VIN=3.6V
0.25
Ω
Switch Current Limit
ISW,CL
VIN=2.5 to 5.5V
1.4
1.6
A
EN High (Enabled the Device)
VEN,HI
VIN=2.5 to 5.5V
1.5
EN Low (Shutdown the Device)
VEN,LO
VIN=2.5 to 5.5V
Input Undervoltage Lockout
VUVLO
rising edge
Input Undervoltage Lockout
Hysteresis
VUVLO,HYST
Thermal Shutdown Temperature
OTP
Maximum Duty Cycle
DMAX
SW Leakage Current
Rev.A.03
V
0.4
Shutdown, temperature increasing
1.8
V
0.1
V
o
160
-1
C
%
100
EN=0V, VIN=5.0V
VSW=0V or 5.0V
V
1
µA
7
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Detailed Description
Main Control Loop
The AME5250A uses a constant frequency, current
mode step-down architecture. Both the main (P-channel
MOSFET) and synchronous (N-channel MOSFET)
switches are intermal. During normal operation, the internal top power MOSFET is turned on each cycle when
the oscillator sets the RS latch, and turned off when the
current comparator resets the RS latch. While the top
MOSFET is off, the bottom MOSFET is turned on until
either the inductor current starts to reverse as indicated
by the current reversal comparator IRCMP.
Pulse Skipping Mode Operation
At light loads, the inductor current may reach zero or
reverse on each pulse.The bottom MOSFET is turned off
by the current reversal comparator, IRCMP, and the switch
voltage will ring. This is discontinuous mode operation,
and is normal behavior for the switching regulator.
Short-Circuit Protection
When the output is shorted to ground, the frequency of
the oscillator is reduced to about 180KHz. This frequency
foldback ensures that the inductor current hsa more time
do decay, thereby preventing runaway. The oscillator’ s
frequency will progressively increase to 1.5MHz when
VFB or VOUT rises above 0V.
Dropout Operation
As the input supply voltage decreases to a value approaching the output voltage, the duty cycle increases
toward the maximum on-time. Further reduction of the
supply voltage forces the main switch to remain on for
more than one cycle until it reaches 100% duty cycle.
The output voltage will then be determined by the input
voltage minus the voltage drop across the P-channel
MOSFET and the inductor.
8
n Application Information
The basic AME5250A application circuit is shown in
Typical Application Circuit. External component selection is determined by the maximum load current and begins with the selection of the inductor value and followed
by CIN and COUT.
Inductor Selection
For a given input and output voltage, the inductor value
and operating frequency determine the ripple current. The
ripple current DIL increases with higher VIN and decreases
with higher inductance.
∆I L =
V
1
× VOUT (1 − OUT )
VIN
f ×L
A reasonable starting point for setting ripple current is
∆IL=0.4(lmax). The DC current rating of the inductor
should be at least equal to the maximum load current
plus half the ripple current to prevent core saturation.
For better efficiency, choose a low DC-resistance inductor.
CIN and COUT Selection
The Input capacitance, CIN is needed to filter the trapezoidal current at the source of the top MOSFET. To
prevent large voltage transients, a low ESR input
capacitorsized for the maximum RMS current must be
used. The maximum RMS capacitor current is given by:
I RMS = I OUT ( MAX ) ×
VI N
VOUT
×
−1
VIN
VOUT
This formula has a maximum at VIN=2VOUT, where
IRMS=IOUT/2. This simple worst-case condition is commonly used for design because even significant deviations do not offer much relief. Note that the capacitor
manufacturer ripple current ratings are often based on
2000 hours of life. This makes it advisable to further
derate the capacitor, or choose a capacitor rated at a
higher temperature than required.
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
The selection of COUT is determined by the effective
series resistance(ESR) that is required to minimize voltage ripple and load step transients. The output ripple,
VOUT, is determined by:
∆VOUT ≅ ∆I L ESR +
1
8 fCOUT
Using Ceramic Input and Output Capacitors
Higher values, lower cost ceramic capacitors are now
becoming available in smaller case sizes. Their high ripple
current, high voltage rating and low ESR make them ideal
for switching regulator applications. However, care must
be taken when these capacitors are used at the input and
output. When a ceramic capacitor is used at the input
and the power is supplied by a wall adapter through long
wires, a load step at the output can induce ringing at the
input, VIN. At best, this ringing can couple to the output
and be mistaken as loop instability. At worst, a sudden
inrush of current through the long wires can potentially
cause a voltage spike at VIN large enough to damage the
part.
Thermal Considerations
In most applications the AME5250A does not dissipate much heat due to its high efficiency. But, in applications where the AME5250A is running at high ambient
temperature with low supply voltage and high duty cycles,
such as in dropout, the heat dissipated may exceed the
maximum junction temperature of the part. If the junction
temperature reaches approximately 160OC, both power
switches will be turned off and the SW node will become
high impedance. To avoid the AME5250A from exceeding the maximum junction temperature, the user will need
to do some thermal analysis. The goal of the thermal
analysis is to determine whether the power dissipated
exceeds the maximum junction temperature of the part.
The temperature rise is given by:
TR = ( PD)(θ JA )
Where PD is the power dissipated by the regulator and
θJA is the thermal resistance from the junction of the die
to the ambient temperature.
Output Voltage Programming
The output voltage is set by an external resistive divider according to the following equation:
VOUT = V REF × 1 +
R1
R2
Where VREF equals to 0.6V typical. The resistive divider allows the FB pin to sense a fraction of the output
voltage as shown in Figure 4.
0.6V ≤ V OUT
≤ 5.5V
R1
FB
AME5250A
R2
GND
Figure 4. Setting the AME5250A Output Voltage
Rev.A.03
9
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
VIN
2.5V to 5.5V
2.2µH
IN
CIN
4.7µF
CER
VIN
2.5V to 5.5V
GND
FB
150K
150K
SW
AME5250A
CFWD
COUT
10µF
CER
CIN
4.7µF
CER
VOUT
1.6V
2.2µH
IN
SW
AME5250A
EN
VOUT
1.2V
EN
GND
FB
CFWD
150K
90K
COUT
10µF
CER
Figure 5. 1.2V Step-Down Regulator
Figure 8. 1.6V Step-Down Regulator
CFWD: 22pF~220pF
CFWD: 22pF~220pF
VIN
3.3V to 5.5V
2.2µH
IN
CIN
4.7µF
CER
VIN
3.6V to 5.5V
GND
FB
COUT
10µF
CER
CIN
4.7µF
CER
EN
VOUT
3.3V
SW
AME5250A
CFWD
150K
100K
2.2µH
IN
SW
AME5250A
EN
VOUT
1.5V
GND
FB
CFWD
150K
33.3K
COUT
10µF
CER
Figure 6. 1.5V Step-Down Regulator
Figure 9. 3.3V Step-Down Regulator
CFWD: 22pF~220pF
CFWD: 22pF~220pF
VIN
2.7V to 5.5V
2.2µH
IN
SW
AME5250A
CIN
4.7µF
CER
EN
VOUT
2.5V
GND
FB
CFWD
150K
47.3K
COUT
10µF
CER
Figure 7. 2.5V Step-Down Regulator
CFWD: 22pF~220pF
10
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
PC Board Layout Checklist
When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the
AME5250A. These items are also illustrated graphically in Figures 10 and Figures 11 . Check the following in your
layout:
1. The power traces, consisting of the GND trace, the SW trace and the VIN trace should be kept short, direct and wide.
2. Does the VFB pin connect directly to the feedback resistors? The resistive divider R2/R1 must be connected between
the (+) plate of COUT and ground.
3. Does the (+) plate of CIN connect to VIN as closely as possible? This capacitor provides the AC current to the internal
power MOSFETs.
4. Keep the switching node, SW, away from the sensitive VFB node.
5. Keep the (-) plates of CIN and COUT as close as possible.
VIN
CIN
L1
IN
AME5250A
EN
VOUT
SW
C1
R1
COUT
FB
VIN
CIN
L1
IN
VOUT
SW
AME5250A
EN
COUT
OUT
COUT
NC
GND
R2
Figure 10. AME5250A Adjustable Voltage
Regulator Layout Diagram
Rev.A.03
NC
GND
Figure 11. AME5250A Fixed Voltage Regulator
Layout Diagram
11
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Application Information
External components selection
Supplier
Inductance
(µ
µH)
Current Rating
(mA)
DCR
(mΩ
Ω)
Dimensions
(mm)
TAIYO YUDEN
2.2
1480
60
3.00 x 3.00 x 1.50
NR 3015
GOTREND
2.2
1500
58
3.85 x 3.85 x 1.80
GTSD32
Sumida
2.2
1500
75
4.50 x 3.20 x 1.55
CDRH2D14
Sumida
4.7
1000
135
4.50 x 3.20 x 1.55
CDRH2D14
TAIYO YUDEN
4.7
1020
120
3.00 x 3.00 x 1.50
NR 3015
GOTREND
4.7
1100
146
3.85 x 3.85 x 1.80
GTSD32
Series
Table 1. Recommended Inductors
Capacitance
(µ
µH)
Package
TDK
4.7
603
C1608JB0J475M
MURATA
4.7
603
GRM188R60J475KE19
TAIYO YUDEN
4.7
603
JMK107BJ475RA
TAIYO YUDEN
10
603
JMK107BJ106MA
TDK
10
805
C2012JB0J106M
MURATA
10
805
GRM219R60J106ME19
MURATA
10
805
GRM219R60J106KE19
TAIYO YUDEN
10
805
JMK212BJ106RD
Supplier
Part Number
Table 2. Recommended Capacitors for CIN and COUT
12
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Characterization Curve
Efficiency vs. Output Current
Efficiency vs. Output Current
100
100
90
90
VIN = 2.7V
70
60
50
40
30
20
V OUT = 2.5V
50
40
30
1
10
100
VOUT = 2.5V
0
1
1000
Efficiency vs. Output Current
Efficiency vs. Output Current
90
VIN = 2.7V
Efficiency (%)
80
70
60
50
40
30
VOUT = 1.5V
10
1
100
60
50
40
30
20
COUT = 10µF L = 2.2µH
10
VIN = 3.6V
70
VOUT = 1.5V
10
0
1000
Output Current (mA)
1
Efficiency vs. Output Current
100
90
90
Efficiency (%)
70
60
50
40
30
V OUT = 1.2V
100
Output Current (mA)
1000
60
50
40
30
VOUT = 1.2V
10
10
100
VIN = 5.5V
70
20
COUT = 10µF L = 2.2µH
10
1
10
Output Current (mA)
80
VIN = 2.5V
20
COUT = 10µF L = 2.2µH
Efficiency vs. Output Current
100
80
Efficiency (%)
1000
100
20
Rev.A.03
100
Output Current (mA)
80
0
10
COUT = 10µF L = 2.2µH
Output Current (mA)
90
Efficiency (%)
60
10
COUT = 10µF L = 2.2µH
100
0
70
20
10
0
VIN = 3.6V
80
Efficiency (%)
Efficiency (%)
80
1000
0
1
10
COUT = 10µF L = 2.2µH
100
1000
Output Current (mA)
13
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Characterization Curve
Frequency vs. Temperature
1.90
0.615
1.85
1.80
1.75
Frequency (MHz)
Reference Voltage (V)
Reference Voltage vs. Temperature
0.620
0.610
0.605
0.600
0.595
0.590
VIN = 3.6V
0.585
0.580
-50
-25
0
+25
+50
+75
+100
1.70
1.65
1.60
1.55
1.50
1.45
1.40
1.35
1.30
1.10
+125
Output Current (mA)
Frequency vs. Supply Voltage
-50
-25
1.70
1.90
1.65
1.89
1.60
1.88
1.55
1.50
1.45
1.40
1.35
1.30
1.25
1.20
1.10
2.5
+75
+100
+125
1.87
1.86
1.85
1.84
1.83
1.82
1.81
1.80
1.79
3.0
3.5
4.0
4.5
5.0
1.77
0
5.5
100
Current Limit (A)
-10
+5
300
400
500
600
700
800
900 1000
Current Limit vs. Temperature
VIN = 3.3V
VOUT = 1.2V
-25
200
Output Current (mA)
Current Limit vs. Temperature
Current Limit (A)
+50
VOUT = 1.8V
VIN = 3.6V
VIN (V)
+20 +35 +50 +65
Temperature ( C)
o
14
+25
1.78
1.15
3.0
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
-40
+0
Output Current (mA)
Output Voltage vs. Output Current
Output Voltage (V)
Frequency (MHz)
VIN = 3.6V
1.25
1.20
1.15
+80 +95 +110 +125
3.0
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
-40
VIN = 3.6V
VOUT = 1.2V
-25
-10
+5
+20
+35 +50
+65 +80
+95 +110 +125
Temperature ( C)
o
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Characterization Curve
Current Limit (A)
Current Limit vs. Temperature
3.0
2.9
2.8
2.7
2.6
2.5
2.4
2.3
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
-40
Light Load Mode Output Voltage Ripple
VIN = 5.0V
VOUT = 1.2V
-25
-10
+5 +20 +35 +50 +65 +80
o
Temperature ( C)
+95 +110 +125
400nS/Div
VIN = 3.6V
VOUT = 1.8V
IOUT = 50mA
1) VSW= 2V/div
2) VOUT = 10mV/Div
3) IL = 500mA/Div
Heavy Load Mode Output Voltage Ripple
400nS/Div
Rev.A.03
Load Step
40µS/Div
VIN = 3.6V
VOUT = 1.2V
IOUT = 1A
VIN = 3.6V
VOUT = 1.8V
IOUT = 0A~1A~0A
1) VSW= 2V/div
2) VOUT = 10mV/Div
3) IL = 500mA/Div
1) VOUT= 100mV/Div
2) IOUT = 500mA/Div
15
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Characterization Curve
Load Step
Load Step
40µS/Div
40µS/Div
VIN = 3.6V
VOUT = 1.8V
IOUT = 50mA~1A~50mA
VIN = 3.6V
VOUT = 1.8V
IOUT = 200mA~1A~200mA
1) VOUT= 100mV/Div
2) IOUT = 500mA/Div
1) VOUT= 100mV/Div
2) IOUT = 500mA/div
Power On from EN
Power Off from EN
400µS/Div
50µS/Div
VOUT = 1.2V
IOUT = 1A
1) EN= 2V/Div
2) VOUT = 500mV/Div
3) IL = 1A/Div
16
VIN = 3.6V
VOUT = 1.8V
IOUT = 1A
1) EN = 2V/Div
2) VOUT = 2V/Ddiv
3) IL = 500mA/Div
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Tape and Reel Dimension
DFN-6D
(2mmx2mmx0.75mm)
P
PIN 1
W
AME
AME
Carrier Tape, Number of Components Per Reel and Reel Size
Package
Carrier Width (W)
Pitch (P)
Part Per Full Reel
Reel Size
DFN-6D
(2x2x0.75mm)
8.0±0.1 mm
4.0±0.1 mm
3000pcs
180±1 mm
QFN-16C
(3mmx3mmx0.75mm)
P
PIN 1
W
AME
AME
Carrier Tape, Number of Components Per Reel and Reel Size
Package
Carrier Width (W)
Pitch (P)
Part Per Full Reel
Reel Size
QFN-16C
(3x3x0.75mm)
12.0±0.1 mm
4.0±0.1 mm
3000pcs
330±1 mm
Rev.A.03
17
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Package Dimension
DFN-6D
(2mmx2mmx0.75mm)
e
b
D
E
L
E1
PIN 1 IDENTIFICATION
D1
TOP VIEW
A
BOTTOM VIEW
G1
REAR VIEW
G
SYMBOLS
A
INCHES
MIN
MAX
MIN
MAX
0.700
0.800
0.028
0.031
D
1.900
2.100
0.075
0.083
E
1.900
2.100
0.075
0.083
e
18
MILLIMETERS
0.650 TYP
0.026 TYP
D1
1.100
1.650
0.043
0.065
E1
0.600
1.050
0.024
0.041
b
0.180
0.350
0.007
0.014
L
0.200
0.450
0.008
0.018
G
0.178
0.228
0.007
0.009
G1
0.000
0.050
0.000
0.002
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Package Dimension
QFN-16C
(3mmx3mmx0.75mm)
e
b
E1
E
k
L
D
D1
PIN 1 IDENTIFICATION
Bottom View
A3
A
A1
Top View
Real View
Real View
SYMBOLS
INCHES
MIN
MAX
MIN
MAX
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.203REF.
0.008REF.
D
2.924
3.076
0.115
0.121
E
2.924
3.076
0.115
0.121
D1
1.600
1.800
0.063
0.071
E1
1.600
1.800
0.063
0.071
k
b
e
L
Rev.A.03
MILLIMETERS
0.200MIN.
0.180
0.280
0.500TYP.
0.324
0.476
0.008MIN.
0.007
0.011
0.020TYP.
0.013
0.019
19
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Lead pattern
DFN-6D
(2mmx2mmx0.75mm)
0.350 BSC
0.800 BSC
1.200 BSC
0.600 BSC
0.650 BSC
1.300 BSC
N1
Note:
1. Lead pattern unit description:
BSC: Basic. Represents theoretical exact dimension or dimension target.
2. Dimensions in Millimeters.
3. General tolerance +0.05mm unless otherwise specified.
20
Rev. A.03
AME
1A, 1.5MHz Synchronous
Step-Down Converter
AME5250A
n Lead pattern
QFN-16C
(3mmx3mmx0.75mm)
0.330 BSC
0.625 BSC
0.500 BSC
2.150 BSC
1.800 BSC
N1
1.800 BSC
Note:
1. Lead pattern unit description:
BSC: Basic. Represents theoretical exact dimension or dimension target.
2. Dimensions in Millimeters.
3. General tolerance +0.05mm unless otherwise specified.
Rev.A.03
21
www.ame.com.tw
E-Mail: sales@ame.com.tw
Life Support Policy:
These products of AME, Inc. are not authorized for use as critical components in life-support
devices or systems, without the express written approval of the president
of AME, Inc.
AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and
advises its customers to obtain the latest version of relevant information.
 AME, Inc. , January 2014
Document: 1283-DS5250A-A.03
Corporate Headquarter
AME, Inc.
2F, 302 Rui-Guang Road, Nei-Hu District
Taipei 114, Taiwan.
Tel: 886 2 2627-8687
Fax: 886 2 2659-2989